U.S. patent number 10,249,865 [Application Number 14/285,779] was granted by the patent office on 2019-04-02 for bus bar module.
This patent grant is currently assigned to YAZAKI CORPORATION. The grantee listed for this patent is YAZAKI CORPORATION. Invention is credited to Shigeyuki Ogasawara, Shinichi Yanagihara.
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United States Patent |
10,249,865 |
Ogasawara , et al. |
April 2, 2019 |
Bus bar module
Abstract
A bus bar module includes: a plurality of bus bar cases each
housing a bus bar; a first engagement portion provided to one of
the plurality of bus bar cases; a first connecting member having
flexibility and connecting the plurality of bus bar cases; a
plurality of insulating covers covering openings of the plurality
of bus bar cases, the insulating covers including a second
engagement portion to be engaged with the first engagement portion;
a second connecting member having flexibility and connecting the
plurality of insulating covers; and a pair of ribs provided to
extend downward from an inner surface of each of the insulating
covers located adjacent to each other.
Inventors: |
Ogasawara; Shigeyuki (Kakegawa,
JP), Yanagihara; Shinichi (Kakegawa, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
YAZAKI CORPORATION |
Minato-ku, Tokyo |
N/A |
JP |
|
|
Assignee: |
YAZAKI CORPORATION (Minato-ku,
Tokyo, JP)
|
Family
ID: |
51935570 |
Appl.
No.: |
14/285,779 |
Filed: |
May 23, 2014 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20140349165 A1 |
Nov 27, 2014 |
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Foreign Application Priority Data
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May 27, 2013 [JP] |
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2013-111111 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01M
2/206 (20130101); H01M 2220/20 (20130101); Y02E
60/10 (20130101) |
Current International
Class: |
H01M
2/20 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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102044693 |
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May 2011 |
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CN |
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102947971 |
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Feb 2013 |
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CN |
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2011-238544 |
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Nov 2011 |
|
JP |
|
2011238544 |
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Nov 2011 |
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JP |
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2013016429 |
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Jan 2013 |
|
JP |
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2012/176935 |
|
Dec 2012 |
|
WO |
|
Other References
Communication dated Dec. 3, 2015 from the State Intellectual
Property Office of the P.R.C. in counterpart application No.
201410228394.6. cited by applicant.
|
Primary Examiner: Gilliam; Barbara L
Assistant Examiner: Zemui; Nathanael T
Attorney, Agent or Firm: Sughrue Mion, PLLC
Claims
What is claimed is:
1. A bus bar module comprising: a plurality of bus bar cases made
of a resin, each bus bar case configured to house a bus bar to
connect a positive electrode of a battery cell and a negative
electrode of an adjacent battery cell among battery cells arrayed
such that the positive electrodes and the negative electrodes of
the battery cells are arranged alternately; a first engagement
portion provided to one of the plurality of bus bar cases; a first
connecting member having flexibility and configured to connect the
plurality of bus bar cases; a plurality of insulating covers made
of a resin, the insulating covers configured to cover openings of
the plurality of bus bar cases and including a second engagement
portion to be engaged with the first engagement portion; a second
connecting member having flexibility and configured to connect the
plurality of insulating covers; and a pair of first ribs provided
to extend downward from an inner surface of each of the insulating
covers located adjacent to each other while interposing the second
connecting member in between, the pair of first ribs configured to
be in contact respectively with inner surfaces of paired walls of
the corresponding bus bar case, the walls extending in a direction
of arrangement of the bus bar cases and facing each other, wherein
the insulating covers are provided with a second rib facing the
second engagement portion in such a manner that the first
engagement portion on the bus bar case is nipped between the second
rib and the second engagement portion.
2. The bus bar module according to claim 1, wherein each of the
first pair of ribs is provided at a position in the insulating
cover close to the second connecting member.
3. The bus bar module according to claim 1, wherein each of the
first pair of ribs includes a reinforcing rib extending from the
inner surface of the insulating cover toward a top portion of the
corresponding wall of the bus bar case, and having such a length
that the reinforcing rib is out of contact with the top portion.
Description
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a bus bar module, or more
specifically, to a structure for engagement between resin bus bar
cases which house bus bars for connecting multiple battery cells in
series and resin covers which cover openings of the bus bar
cases.
Background Art
A battery pack (also referred to as an assembled battery or a
battery unit) formed by connecting multiple battery cells in series
is used as a direct-current power source for driving an electric
motor in an electric vehicle, a hybrid car or the like. As
described in Japanese Patent Application Publication No.
2011-238544 (Patent Document 1), such a battery pack is fabricated
by forming a battery assembly in which positive electrodes and
negative electrodes of multiple battery cells alternately arranged
side by side are bundled and the positive electrodes and the
negative electrodes of the adjacent battery cells are connected in
series by using conductive bodies called bus bars, and, if
necessary, by housing the battery assembly in a housing. Then, the
battery pack is put to use.
The bus bars are respectively housed in box-shaped bus bar housing
units (hereinafter referred to as bus bar cases) made of an
insulative resin. The bus bar cases are connected in an arrangement
direction of the battery cells by using U-shaped flexible
connecting members. Then, a bus bar module is formed in such a way
that: the columnar positive and negative electrodes of the battery
cells are inserted into holes formed in the bus bars, and are fixed
thereto with nuts or the like; and the bus bars and the electrode
members exposed on an opening side of the bus bar cases are
protected by being covered with plate-shaped insulating covers In
particular, the insulating covers are formed as multiple separate
covers each for a plural number of bus bar cases set appropriately
in consideration of a dimensional tolerance of the battery unit.
The separate insulating covers are connected to one another using
flexible connecting members. Moreover, each insulating cover
includes a second engagement portion to be engaged with a first
engagement portion provided to a given one of the bus bar cases.
The bus bar module is formed by engaging the first and second
engagement portions (hereinafter referred to as a lock mechanism as
appropriate) with one another.
SUMMARY OF THE INVENTION
However, the bus bar module described in Patent Document 1 does not
consider that the engagement of the lock mechanism may be released
for some reason in the course of assembling a bus bar module by
engaging the corresponding engagement portions of the insulating
covers and the bus bar cases with one another. Specifically, there
may be a case where the lock mechanism for at least one of two
adjacent insulating covers is unlocked and the unlocked insulating
cover is displaced relative to the corresponding bus bar case due
to a deformation of the connecting member. If the insulating cover
is displaced relative to the openings of the bus bar cases as
described above, the columnar electrodes and the bus bars are
exposed. The exposure of the columnar electrodes and the bus bars,
to which a battery voltage is being applied, disturbs attachment
work of the bus bar module and should therefore be avoided as much
as possible.
An object of the present invention is to provide a bus bar module,
which is capable of preventing exposure of a columnar electrode and
a bus bar, the exposure being likely to occur due to displacement
of an insulating cover relative to a bus bar case in the course of
assembling the bus bar module by engaging a lock mechanism for the
insulating cover and the bus bar case.
An aspect of the present invention is a plurality of bus bar cases
made of a resin, each bus bar case configured to house a bus bar to
connect a positive electrode of a battery cell and a negative
electrode of an adjacent battery cell among battery cells arrayed
such that the positive electrodes and the negative electrodes of
the battery cells are arranged alternately; a first engagement
portion provided to one of the plurality of bus bar cases; a first
connecting member having flexibility and configured to connect the
plurality of bus bar cases; a plurality of insulating covers made
of a resin, the insulating covers configured to cover openings of
the plurality of bus bar cases and including a second engagement
portion to be engaged with the first engagement portion; a second
connecting member having flexibility and configured to connect the
plurality of insulating covers; and a pair of ribs provided to
extend downward from an inner surface of each of the insulating
covers located adjacent to each other while interposing the second
connecting member in between, the pair of ribs configured to be in
contact respectively with inner surfaces of paired walls of the
corresponding bus bar case, the walls extending in a direction of
arrangement of the bus bar cases and facing each other.
Each of the pair of ribs may be provided at a position in the
insulating cover close to the second connecting member. Each of the
pair of ribs may include a reinforcing rib extending from the inner
surface of the insulating cover toward a top portion of the
corresponding wall of the bus bar case, and having such a length
that the reinforcing rib is out of contact with the top
portion.
According to the present invention, it is possible to prevent
exposure of the columnar electrode and the bus bar, the exposure
being likely to occur due to displacement of the insulating cover
relative to the bus bar case in the course of assembling the bus
bar module by engaging the lock mechanism for the insulating cover
and of the bus bar case.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing an external appearance of a
bus bar module according to an embodiment of the present
invention.
FIG. 2 is a perspective view showing inner surface sides of
insulating covers of the bus bar module of FIG. 1.
FIG. 3 is a transparent view showing ribs provided to the
insulating covers according to the embodiment of the present
invention.
FIGS. 4A and 4B are views of the ribs of FIG. 3, which are viewed
from the line IV-IV in FIG. 3.
FIGS. 5A and 5B are views for explaining configurations of a lock
mechanism for the insulating cover and of a bus bar case.
DESCRIPTION OF EMBODIMENTS
A bus bar module according to an embodiment of the present
invention will be described below with reference to the
accompanying drawings. A bus bar module 1 of the embodiment of the
present invention is attached to positive and negative columnar
electrodes projecting from a top portion of a battery assembly (not
shown), for example. In the battery assembly, positive electrodes
and negative electrodes of battery cells are alternately arranged.
A positive electrode of a battery cell and a negative electrode of
an adjacent battery cell are connected to each other with a
conductor plate called a bus bar. Thus, the multiple battery cells
are connected in series. The positive electrode and the negative
electrode of each battery cell in the battery assembly are located
in a direction orthogonal to the arrangement direction. In other
words, the electrodes of the battery cells are arranged in two rows
in the arrangement direction. Accordingly, the bus bar module 1
includes two rows of bus bar case assemblies 2a and 2b located
parallel to the arrangement direction of the battery assembly. Each
of the bus bar case assemblies 2a and 2b includes multiple bus bar
cases 3 made of a resin, each of which is configured to house the
corresponding bus bar. Each two adjacent bus bar cases 3 are
connected to each other with a flexible connecting member (a first
connecting member) 4. The bus bar case assemblies 2a and 2b are
formed substantially into the same structure except for the
respective end portions. Given this fact, the bus bar module of the
embodiment will be described by using the bus bar case assembly 2a
shown in FIG. 1 as an example. Note that the bus bar case assembly
2a and the bus bar case assembly 2b are formed symmetrically with
respect to the arrangement axis of the battery assembly.
The bus bar case assembly 2a includes the multiple bus bar cases 3,
and the connecting members 4 each of which connects an adjacent
pair of the bus bar cases 3. The connecting members 4 are flexible.
As shown in FIG. 4A, each connecting member 4 is formed integrally
with two ends of the adjacent bus bar cases 3. The connecting
member 4 includes a strip-shaped portion 4a formed into an inverted
U-shape. The strip-shaped portion 4a protrudes to an upper end side
of the bus bar cases 3. However, the shape of the connecting
members 4 is not limited only to this example. The connecting
members 4 may adopt various structures (shapes) as long as the
structures can establish the connection with such a strength that
the adjacent bus bar cases 3 can change their relative positions to
each other. Meanwhile, the bus bar cases 3 are provided with wire
routing paths 5 located on the near side in FIG. 1. The wire
routing paths 5 house wires for detecting voltages of the battery
cells. The wire routing paths 5 are formed integrally with the
respective bus bar cases 3. Each wire routing path 5 is provided
with a lid 6 which is made openable and closable. The lid 6 is
connected to a side edge of the corresponding bus bar case 3 with a
flexible hinge. The lid 6 is locked to a side surface of the
corresponding wire routing path 5 in an attachable and detachable
manner using engagement portions 7.
Three insulating covers 10 are provided in this embodiment. In the
following description, these insulating covers may be occasionally
referred to as insulating covers 10a, 10b, and 10c for the sake of
convenience. The insulating covers 10 cover openings of the bus bar
cases 3. Each insulating cover 10 of the embodiment is provided to
cover a half of the lid 6 of each wire routing path 5. The
insulating covers 10 are formed to cover the entirety of the
openings of the multiple (four or five in the illustrated example)
bus bar cases 3. Each insulating cover 10 is made of an
electrically insulative resin. Each two adjacent insulating covers
10 are connected to each other with a flexible connecting member (a
second connecting member) 11. Each insulating cover 10 includes at
least one second engagement portion 12 serving as a lock unit. Such
a second engagement portion 12 is engaged with a corresponding
first engagement portion 8 provided on one of the multiple bus bar
cases 3. Each of the insulating covers 10a and 10c is provided with
two second engagement portions 12 while the insulating cover 10b is
provided with one second engagement portion 12. The bus bar cases 3
to be engaged with these second engagement portions 12 are provided
with the first engagement portions 8 as shown in FIGS. 5A and 5B,
for example. Each second engagement portion 12 has a shape of a
hole, a groove, or the like into which the corresponding first
engagement portion 8 is fitted. As shown in FIG. 5B, for instance,
the second engagement portion 12 is formed into a shape of a flat
plate-shaped and hollow frame. As shown in FIG. 5B, each first
engagement portion 8 is provided to protrude outward from a side
wall 9 of the bus bar case 3. The first engagement portion 8 is
formed into a shape of a claw, for example. The first engagement
portions 8 are provided on the bus bar cases 3 at positions
corresponding to the insulating covers 10a, 10b, and 10c. Moreover,
when the insulating covers 10a, 10b, and 10c cover the openings of
the bus bar cases 3, the claws of the first engagement portions 8
on the bus bar cases 3 are engaged with beams of the second
engagement portions 12 on the insulating covers 10, whereby the
insulating covers 10 are locked to the bus bar cases 3. Here, the
first engagement portion 8 and the second engagement portion 12 are
apt to be unlocked if engagement therebetween is inadequate. Hence,
the insulating covers 10 may be provided with ribs 13 as shown in
FIG. 5B. Each rib 13 is provided facing the corresponding second
engagement portion 12 in such a way that the engagement portion 8
on the bus bar case 3 is nipped between the rib 13 and the second
engagement portion 12. Thus, the first engagement portion 8 and the
second engagement portion 12 become less likely to be unlocked.
FIG. 3 is a transparent view illustrating a state where the
openings of the bus bar cases 3 are covered with the insulating
covers 10, which is viewed from an outer surface side of the
insulating covers 10. As shown in FIG. 3, the adjacent insulating
covers 10 (10a and 10b, for example) are connected to each other
with the flexible connecting member 11. The connecting member 11
includes strip-shaped portions 11a and 11b, which are formed into
U-shaped portions facing each other and are located between outer
surfaces of opposed cover walls of the adjacent insulating covers
10.
Each of the bus bar cases 3 includes a pair of walls 3a and 3b
which extend in the arrangement direction of the bus bar cases 3
and face each other. In other words, the walls 3a and the walls 3b
are provided in the arrangement direction of the bus bar cases 3,
respectively. Each bus bar 21 is placed between the corresponding
pair of walls 3a and 3b. As shown in FIG. 4A, a pair of ribs 14a
and 14b are provided on inner surfaces of the insulating covers 10
(10a and 10b, for example) that are adjacent to each other while
interposing the connecting member 11 in between, and at positions
of the aforementioned inner surfaces in contact with inner surfaces
of the pair of walls 3a and 3b. Each of the ribs 14a and 14b is
formed into a flat plate shape, and extends downward from the inner
surface of the corresponding insulating cover 10 to the bus bar 21
(or a terminal 23). Meanwhile, each pair of ribs 14a and 14b are
provided at the positions close to the connecting member 11 for
connecting the adjacent insulating covers 10. In other words, each
pair of ribs 14a and 14b are provided at end portions of the
corresponding insulating cover 10 to be connected to the connecting
member 11. Moreover, as shown in FIG. 4B, each of the ribs 14a and
14b includes a reinforcing rib 15, which projects perpendicularly
from a surface of the rib (a surface facing the wall 3a (3b)). The
reinforcing rib 15 extends from the inner surface of the insulating
cover 10 toward a top portion of the wall 3a (3b) of the bus bar
case 3. The reinforcing rib 15 has such a length that the
reinforcing rib 15 can be out of contact with the top portion of
the wall 3a (3b). Here, claws 25 for holding the bus bar 21 at a
predetermined position are provided on inner surfaces of the bus
bar case 3.
Procedures for assembling the bus bar module 1 will be briefly
described. First, the bus bar case assemblies 2a and 2b integrally
provided with the wire routing paths 5 are attached to the columnar
electrodes (not shown) of the battery assembly. At this time, the
columnar electrodes of the adjacent battery cells are positioned
and inserted respectively into two holes 22 provided in each bus
bar 21 shown in FIG. 5A. Moreover, a voltage detection terminal 23
is brought in through a slit 24 provided in the wall 3a of each bus
bar case 3, and is attached to the columnar electrode that is
inserted into one of the holes 22. The terminal 23 is connected to
a voltage detection wire which is routed in the wire routing paths
5. Then, the bus bars 21 and the terminals 23 are connected to the
battery cells by screwing nuts onto threads on the columnar
electrodes. Subsequently, the second engagement portions 12 of the
insulating covers 10 are aligned with the first engagement portions
8 of the corresponding bus bar cases 3. Thereafter, the insulating
covers 10 are attached and locked to the opening surfaces of the
bus bar cases 3 sequentially from one end side of the bus bar
module 1, for example. At this time, the pair of ribs 14a and 14b
provided on the inner surface of the given insulating cover 10 are
positioned to come into contact with the inner surfaces of the
walls 3a and 3b of the corresponding bus bar case 3. Then, the
insulating cover 10 is pushed into the bus bar case 3. Thus, the
first and second engagement portions 8 and 12 are engaged with and
locked to each other.
According to the embodiment of the present invention, even if the
first and second engagement portions 8 and 12 as a lock mechanism
for at least one of two adjacent insulating covers 10 are unlocked
in the course of assembling the bus bar module 1, the pair of ribs
14a and 14b provided on the inner surface of the relevant
insulating cover 10 remain in contact with the corresponding bus
bar case 3. As a consequence, a relative position between the
insulating cover 10 and the bus bar cases 3 is not displaced unless
the insulating cover 10 is pulled up to a position where the pairs
of ribs 14a and 14b are detached from the bus bar cases 3. Thus, it
is possible to prevent exposure of the columnar electrodes and the
bus bars in the bus bar cases 3.
In other words, if at least one of the lock mechanisms for two
adjacent insulating covers 10 and the corresponding bus bar cases 3
is unlocked, the unlocked insulating cover 10, without the pairs of
the ribs 14a and 14b provided, is apt to be displaced relative to
the opening surfaces of the bus bar cases 3 due to a deformation of
the connecting member 11. If such displacement is significant, the
columnar electrodes and bus bars in the bus bar cases 3 are
exposed. The exposure of the columnar electrodes and the bus bars,
to which a battery voltage is being applied, disturbs attachment
work of the bus bar module. On the other hand, according to the
embodiment, it is possible to avoid exposure of the columnar
electrodes and the bus bars, to which the battery voltage is being
applied, by restricting relative displacement between the
insulating covers 10 and the opening surfaces of the bus bar cases
3. In particular, according to the embodiment, each pair of ribs
14a and 14b are provided in the vicinity of the corresponding
connecting member 11 where the displacement of the insulating cover
10 reaches a maximum. Thus, the relative displacement of the
insulating cover 10 from the opening surfaces of the bus bar cases
3 can be reduced. In addition, the reinforcing ribs 15 are provided
so as to reinforce the pairs of the ribs 14a and 14b. As a
consequence, the pairs of ribs 14a and 14b can be made thin.
Although the present invention has been described on the basis of a
certain embodiment, it is obvious to those skilled in the art that
the invention is not limited only to the above-described embodiment
but can also be embodied in various other modes that are modified
or changed within the scope of the gist of the present invention.
It should be naturally understood that such modified or changed
modes are also encompassed by the scope of the appended claims.
* * * * *